Imagine you owe on five credit cards, you owe five debts. So which debt should you pay first? And the answer is very simple: You should pay the one with the highest interest rate first. But that's not what people do.

Kids don't care what party they have, right? They want cake and they want to run around. Nothing else matters. But in this escalation, all the kids want parties like their friends. So, if all the friends have an amazing, expensive party, they all want the same thing. If we all got to scale down as a coordinated effort, all the kids would have been just as happy.

The most difficult thing is to recognize that sometimes we too are blinded by our own incentives. Because we don’t see how our conflicts of interest work on us.

Money is a great way to get happiness. Right? Lots of wonderful things you can do with money. The question is, are we really optimizing on that? So, if you think about getting lattes and getting cable. Which one of those is actually giving you a greater happiness, and if you have to cut on one of those, which one would you cut? So, I think thinking in terms of concrete terms would help us a great deal.

Interesting thing that is happening in American society is that people are starting to talk about money. I don't know how you feel about this, but for a long time, nobody was talking about money. It was a secret. And it's kind of very interesting because we do lots of stuff to portray to people about how much money we have, the clothes we wear and the cars we have and the house - they all kind of depict to other people, signal how much money we make, but we don't talk about it specifically.

We can think about how we reduce the pain in paying. So, for example, credit cards are wonderful mechanisms to reduce the pain of paying. If you go to a restaurant and you are paying cash, you would feel much worse than if you were paying with credit card. Why? You know the price, there's no surprise, but if you're paying cash, you feel a bit more guilt.

The retail industry has its own headache: it loses $16 billion a year to customers who buy clothes, wear them with the tags tucked in, and return these secondhand clothes for a full refund.